パクス・ブリタニカの転換期 -一八六〇年代のイギリス外交とパーマストン卿-

After the Napoleonic War, Great Britain was a balancer of the Concert of Europe under the Vienna Settlement. However, this settlement had deteriorated, between the 1830s and the 1860s, until the German Empire of Bismarck created a new order in the European balance of power from the 1870s. While the Vienna Settlement was being preserved, the main British actor in European international relations was the third Viscount Palmerston, who was Foreigh Secretary 1830-34, 35-41, 46-51 and also Prime Minister 1855-58, 59-65 in Britain. He exaggerated his ‘gunboat diplomacy’ to maintain the British interest of free trade all over the world until the 1850s. In spite of his ambition to control the Concert of Europe in the 1860s Palmerston had to abandon a strong line of foreign policy in his last years, and Britain was obliged to adopt a passive, non-intervention posture towards continental affairs for a while. Various theory have been designed to elucidate the reason of British non-intervention diplomacy of the 1860s: the decline of British hegemony in the world, cautious opinions of the Queen and people, cautious diplomacy of Palmerston, himself, and his suspicion toward the French Emperor, Napoleon III. In addition to these arguments, we must investigate the political position of Lord Palmerston withih party politics in the age of his second ministry, 1859-65, to understand British isolationist diplomacy, which was the most interesting contrast with her former policy of the 1830s or 1840s.<br>In fact, Lord Palmerston had to survive in the extremely difficult and unstable world of British party politics of the early 1860s. The Liberal Party was founded just before the formation of his second administration and consisted of not only the Whigs, his own group, but also the Peelites and the Radicals who had opposed Palmerston's gunboat diplomacy for a long time since the 1840s. In order to regulate the conflict among these groups within the Liberals, the prime minister could not control the foreign decision-making without consulting his Foreign Secretary, Earl Russell, or Cabinet which included many cautious ministers, unlike his first ministry. On the other hand, Palmerston tried to restrain the parliamentary and financial reforms of the Peelites or Radicals in his party because of his conservative anti-reform principle, however, he could not stand against the reformers on his own. Therefore, he contacted the Earl of Derby, the Conservative Leader of the Opposition, to stop these radical reforms together, and Palmerston had to accept Derby's requirement of non-intervention diplomacy in exchange for Conservative cooperation.<br>This article investigates the unstable situation of Lord Palmerston, who had to be well-balanced between his cautious ministers and the Conservatives when he decided foreign policy, on British party politics in the 1860s. Palmerston was required to adopt moderate non-intervention diplomacy at the time of the Italian Unification War, the American Civil War, the Polish Insurrection and the Danish-German War, even though he wished to interfere, under the strict neutrality policy of the ‘Palmerston-Derby alliance’. Even after the end of the alliance following the death of Palmerston in October 1865, British non-intervention policy was maintained by cautious leaders, like Derby or Clarendon, and Britain never intervened in continental affairs in the 1860s. It has been termed the decline of British global hegemony.